REDMOND — Bill Gates has made public appearances at Microsoft relatively rarely since leaving his day-to-day role at the company five years ago, and in many cases his talks here have been connected to specific topics such as philanthropy.

But the Microsoft chairman is back on the Redmond campus today to deliver the keynote talk at the Microsoft Research Faculty Summit. The topic is a pretty broad one: “Innovation and Opportunity: The Contribution of Computing to Improving Our World.”

Gates’ talk comes against the backdrop of Microsoft’s massive corporate reorganization, announced last week by Microsoft CEO Steve Ballmer. Those changes aren’t likely to be a major topic of the conversation (and may not be a topic at all) but the event will underscore some of the changes: Rick Rashid, the longtime Microsoft Research chief who is taking a new role in the operating systems group, will moderate the talk with Gates.

The Faculty Summit event attracts academic researchers from around the world to connect with Microsoft Research.